\(\mathrm{Mr}\) Brown has just finished paying off his twenty-year home loan which was R400 000. During the first five years the interest rate was \(24 \%\) per annum compounded monthly. Thereafter, and for the rest of the term, the interest rate decreased to \(18 \%\) per annum compounded monthly.
(a) Calculate his initial monthly payment.
(b) Calculate his balance outstanding at the end of December in the fifth year.
(c) When the interest rate changed after five years, Mr Brown was able to pay a decreased monthly payment starting at the end of January in the sixth year. Calculate what this new repayment was.